moved HasTransparentBackground() from wxUniv to common wxWindow

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@31272 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/window.tex

@@ -1326,7 +1326,6 @@ Returns {\tt true} if this window has the current mouse capture.
 
 \constfunc{virtual bool}{HasScrollbar}{\param{int }{orient}}
 
-
 Returns {\tt true} if this window has a scroll bar for this orientation.
 
 \wxheading{Parameters}
@@ -1334,6 +1333,18 @@ Returns {\tt true} if this window has a scroll bar for this orientation.
 \docparam{orient}{Orientation to check, either {\tt wxHORIZONTAL} or {\tt wxVERTICAL}.}
 
 
+\membersection{wxWindow::HasTransparentBackground}\label{wxwindowhastransparentbackground}
+
+\constfunc{virtual bool}{HasTransparentBackground}{\void}
+
+Returns \true if this window background is transparent (as, for example, for
+wxStaticText) and should show the parent window background.
+
+This method is mostly used internally by the library itself and you normally
+shouldn't have to call it. You may, however, have to override it in your
+wxWindow-derived class to ensure that background is painted correctly.
+
+
 \membersection{wxWindow::Hide}\label{wxwindowhide}
 
 \func{bool}{Hide}{\void}